1. Field of the Invention
The present invention relates to an actinic ray- or radiation-sensitive resin composition, an actinic ray- or radiation-sensitive film and a method of forming a pattern using the same. More specifically, the present invention relates to an actinic ray- or radiation-sensitive resin composition that is suitable for use in a process for producing a semiconductor for an IC or the like, a process for producing a circuit board for a liquid crystal, a thermal head or the like, other photofabrication processes, a process for producing a planographic printing plate and as a composition that is hardened by acid, and also relates to an actinic ray- or radiation-sensitive film and a method of forming a pattern using the same. Furthermore, the present invention relates to a process for manufacturing an electronic device including the method of forming a pattern and an electronic device manufactured by the process.
2. Description of the Related Art
A chemical amplification resist composition is a pattern forming material that is capable of, upon exposure to far ultraviolet or other radiation, generating an acid at the exposed area and, by a reaction catalyzed by the acid, changing the solubility in a developer between the area having been exposed to actinic radiation and the nonexposed area to thereby attain pattern formation on a substrate.
In the use of a KrF excimer laser as an exposure light source, a resin whose fundamental skeleton consists of a poly(hydroxystyrene) exhibiting a low absorption mainly in the region of 248 nm is employed as a major component. Accordingly, there can be attained a high sensitivity, high resolving power and favorable pattern formation. Thus, a system superior to the conventional naphthoquinone diazide/novolak resin system is realized.
On the other hand, in the use of a light source of a further shorter wavelength, for example, an ArF excimer laser (193 nm) as an exposure light source, as the compounds having an aromatic group inherently exhibit a sharp absorption in the region of 193 nm, the above-mentioned chemical amplification system has not been satisfactory. Therefore, resists for an ArF excimer laser containing a resin with an alicyclic hydrocarbon structure have been developed.
A variety of compounds have been developed as a photoacid generator being a main constituent of the chemically amplified resist composition (see, for example, patent references 1 and 2). For example, patent reference 1 describes photoacid generators comprised of sulfonium salts each having an ether structure in its sulfonium cation.
However, discovering an appropriate combination of used resin, photoacid generator, basic compound, additive, solvent, etc., from the viewpoint of comprehensive performance as a resist is extremely difficult, and the current situation is that any combination is still unsatisfactory. For example, there is a demand for the development of a resist excelling in exposure latitude and pattern roughness characteristic, such as line width roughness (LWR), and ensuring less occurrence of particles over time. Moreover, when a liquid-immersion exposure is performed, the acid generated upon exposure to light may be eluted into the immersion liquid to thereby cause the problems of pattern shape deterioration and exposure machine contamination. Therefore, a resist composition ensuring less elution of generated acids into the immersion liquid is desired.